Ask if the other is lying.
The liar would tell you he is telling the truth, the honest one would also, back to square one.
Or... She beats them both up, goes a little ways down each path, if she sees the kingdom she's on the way to happiness, if she doesn't then she can turn around and take the other road

Problem: When the first step is taken on either path, the other one is hidden from your view, along with those crazy twins.
Or... she could go see the wizard who tells her to follow the yellow brick road
The wizard is so happy with his new cell phone plan, he talks, and talks, but not to you.
Or... She could climb a tree and look for the kingdom from the top of it
The tree is magic and shakes her to the ground, and having no health coverage, the twins (both Dr's) cannot help her, she dies, they can smell her in the Fling kingdom.
Or... She can use the available resources McGuyver style and make an aircraft device where she can then hover in the skies to look for the kingdom and just fly to it
I bought one of those from wOOt, it is just not as big and powerful as advertised, CRASH, see answer above.
Or... I'm just being goofy
